# 方法1
a = 1
b = 2
c = {'a': a, 'b': b}
a = c['b']
b = c['a']
print(a, b)

# 方法2
a = 3
b = 5
a, b = b, a
print(a, b)

# 方法3
a = 1
b = 2
t = a
a = b
b = t
print(a, b)
